Often in the plastics industry, the final color of the plastic part is introduced into the plastic forming the part just prior to the extrusion or injection molding thereof. Because the dyes most often are introduced as concentrated granulars, pellets, flakes or powder, the dyes are messy and difficult to handle. This causes problems where it is necessary to change colors during the extruding or injection molding of the plastic parts. The dyes used in the plastics industry are usually messy and difficult to clean, thereby requiring an excessive amount of down time to change dyes or to alter the apparatus where that action is desirable. For this reason, there has been a need in the art to provide a system which permits easy changing of the dye stock and also permits changing of the colors without mixing colors and having residual amounts of the old dye present in the system to mix with the new color. Until the present time, there has not been available a system which permits easy interchanging of the various colored dyes without the attendant difficulty of clean-up and the like. An additional problem is that often it is desirable to introduce the dyes into the main plastic material in varying amounts. This means that the dye stock must be driven at different rates of speed and may require that the apparatus forming the dye metering system be altered. No equipment presently known or available permits easy interchanging of drive systems to facilitate the wide variety of volumetric flow rates necessary for the various colored dyes.